THE little stream from which the city of Oneida, New York, receives its water supply, and also the reservoir, are located in the midst of the Salina shales. In some places these shales contain considerable quantities of gypsum, many times quite large masses of selenite.

The Soil Survey of Madison County, New York, issued by the Government Printing Office of Washington in 1907, contains an account of the geology of the region. It is there stated that the ravine occupied by the city reservoir is Upshar clay, the sides of the surrounding slope are Allis clay, and the higher portion of the watershed Miami stony loam. The Upshar clay is derived directly from the disintegration and weathering in place of the red Salina shales of the Silurian Age. The Allis clay is formed by the weathering in places of the light coloured Salina shales.

The Miami stony loam is derived from the weathering in place of a comparatively heavy mantle of glacial material deposited as a terminal moraine by one of the later advances of the ice-sheet at about the close of the glacial epoch in this section. It is not likely that the hard local limestones have contributed any considerable amount of material to the formation of the till, but that the soft red shales along the foot hills have contributed to it is evident from its colour. It is, however, quite probable that the limestone now contributes to the soil or soil solution.

The character of the soil in which the reservoir is located as well as that of the watershed itself accounts for the large amount of hardness in the form of calcium sulphate and calcium and magnesium carbonates. It is necessary to employ water softening plants in order to use the water in the manufacturing industries of the city, and also in the engine boilers of the different railway lines. The analysis of the water is given in Table I.

TABLE I.-Parts per Million.

109

necessary to meet the needs of the growing city another reservoir to hold five hundred millions of gallons can be constructed farther up the stream. The watershed is very sparsely settled, scarcely containing one residence per square mile, and the danger of contamination is accordingly very slight. The sides of the stream are steep and wooded, and the bed is rocky for the most part and the current is quite swift. An analysis of the water gave the results shown in Table II.

TABLE II.-Parts per Million. Total solids

CaSO4

CaCO3

MgCO3

Fe203..

SiO 2

71.6

12.8

28.77

14'98

1.16

2.20

While unusually hard the water shows rather unusual freedom from organic contamination.

The proposed supply for the city, the water from Florence Creek, is of a very different quality. It is about about 20 miles north of the City of Oneida. The stream is 14 miles long, and the watershed averages one and a fourth miles in width, comprising an area of 17 square miles. In the locality of the stream the rainfall makes an average flow of one million gallons daily for each square mile of watershed, so the daily average would be seventeen millions of gallons.

OUR ANALYTICAL CHEMISTRY AND ITS

FUTURE.*

By W. F. HILLEBRAND, Ph.D.f Chief Chemist of the Bureau of Standards, Washington, U.S.A.

IN an address (Journ. Am. Chem. Soc., 1905, xxvii., 300) read at Philadelphia nearly twelve years ago, I gave expression to some thoughts on the condition of analytical chemistry in our country as the condition appeared to me then to be. Those thoughts were based on an experience of many years, during which I was engaged wholly in analytical work of a more than ordinarily exacting nature, and especially upon observations that had been acquired in connection with several series of co-operative analyses of diverse materials. Since then my attention has been

The Chandler Lecture, 1916, delivered before the Columbia University. U.S, A.

To several of my colleagues in the Bureau of Standards, to whom the first draft of this address was submitted, I am under obligations

no less given to analysis, largely for the past eight years in a supervisory capacity however, and I have had opportunity to note the conditions that now prevail with respect to chemical analysis and what an important bearing exact analytical work often has on problems of physical and electro-chemistry, metallurgy, &c.

It seems to me, then, that I can choose no more fitting subject for my present discourse than a continuation of one so closely related to my life-work, one in which I feel a deep interest and of which I may be presumed to have knowledge somewhat worth presenting on an occasion like this. Then, too, since my remarks will apply most directly to analysis as it concerns the producers of the raw materials and the users of the products of applied science, the subject is eminently a proper one for the present occasion, and particularly so in an institution where applied chemistry made one of its important starts in this country, in the old School of Mines, with which the name of Chandler is so inseparably connected.

Although I shall cover now some of the ground traversed in my address of twelve years ago, in briefly alluding to the conditions of analytical chemistry in the present year, 1916, there is much to be said in developing one or two of the ideas then simmering in my mind and other phases of the general subject not then mentioned. So my subject calls for a more unrestricted title than I gave it at that time, and I shall speak to you of our analytical chemistry and its future, purposely restricting myself to a consideration of conditions as they exist and may become in this country.

In the early days of chemistry there was needed a vast accumulation of observations to serve as foundations for the development of the science. At the very basis lay the need for knowledge of the composition of all kinds of matter. Hence it came about that many, if not most, of the great chemists of the time were of necessity analysts, and the analytical branch of chemistry stood in high repute. That this condition did not maintain itself, that chemical analysis during the latter half of the past century fell from its high estate and came to be looked upon more or less as a handy tool for ulterior ends, a tool, moreover, which need not for most purposes be of the sharpest or the best, or entrusted only to the most careful and skilled operators-all this has been recognised and lamented by many. The reasons for the fall are also well enough known and need not be discussed at length, but brief reference to some of them will be needed in view of later remarks.

Chief among the reasons for the neglect of analytical chemistry is the enormous development, first of organic chemistry and later of the so-called physical chemistry. The effect was brought about in two ways: --(1) by mere displacement, as it were, owing to the far greater promise of new discoveries, however commonplace, or because of the strong interest attaching to new and unexplored fields of inquiry; (2) by the unfortunate fact that for a long period approximate analytical results were thought to suffice in most of the industries, and even in scientific researches. This meant that slipshod work and methods came more and more into use and less fundamental knowledge of analysis seemed to be demanded of chemistsall of which reacted unfavourably upon the standing of the analytical profession, tending to discredit it as a whole, even though it held members fit to rank with the illustrious pioneers.

In addition, some chemists came to feel that the field was an exhausted one, offering little to reward the research worker. How little this is true the events of recent years have abundantly shown. The growing sense of the important influence of small, even minute, amounts of this or that element or combination in a given material. and the high value of many ores and commercial products, has led to more critical examination of the methods used for determining the content of the substances in question in order to ascertain with greater precision the value of those materials, just as had been done long before for the

precious metals, gold and silver. Such examination revealed not infrequently unsuspected defects in methods regarded hitherto as reliable and accurate, and that good results were due often to compensation of errors or were to be had only within a narrow range of conditions. One good effect of such investigations has been to make conservative analysts distrustful of all new methods and less reliant on some of the old ones until their worth and suit. ability have been put to far more crucial test than was formerly deemed necessary.

Yet notwithstanding improvements made in important methods through painstaking research, it is evident that many methods will require a study differently directed or more profound than any yet made before light enough to meet even our immediate needs is thrown upon them. And who shall say what needs another century or even decade may bring forth? Are we not again and again even now confronted with the need to determine smaller and smaller amounts of a component and to make more and more perfect separations in order that the first may be possible? Are we to assume that a limit has been reached?

Another fact shows how untrue it is that the field of chemical analysis has little new to offer. Few ever thought, not so long ago, to lock for the rarer elements in an ore or industrial product made from the ores. No use whatsoever was made of certain elements that are now serving most useful ends, either by themselves or in combinations. There are other elements, still chemical curiosities, for which no use has yet been found. Is there any more reason to believe for them than for the others that uses will never be found? Rare though they be, like gallium, indium, and germanium, and costly their extraction, the finding of a use for them will broaden the search for their ores and lessen the cost of production. With use will come a demand for methods of separation and determination, which must be accurate because of the small percentages in question or the enormous value of the material.

But there are other fields in which the chemist has to look to analysis of the highest order for help in solving his problems. For instance, the importance of exact analytical methods in connection with physico-chemical researches is very great and is, perhaps, best illustrated in the preparation of pure materials. There is no question that physical constants, even atomic weights, have been determined, not infrequently, upon materials of doubtful or at least unproved purity. The practice is all too common of assuming that a certain number of crystallisations or distillations is sure to yield a product of highest purity. Conclusive results can be obtained only when methods are devised and applied by which the amounts of any possible contaminant present can be proved to be without influence upon the results sought. A single instance, borrowed from the experience of the Bureau of Standards, may be of interest. In the preparation of pure alcohol to be used in the determination of a series of densities, tests were devised or confirmed for detecting the presence of minute amounts of ether, aldehyd, methyl alcohol, and water. The most delicate test for the latter was found to be the critical solution temperature of mixtures of kercsene and the alcohol to be tested. By this means the presence of o‘001 per cent of water in the alcohol could be readily detected."

In the field of electro chemistry there is a similar need for exact analytical data. In the determination of the electro-chemical equivalent of silver, from which the value of the ampère is derived, researches extending over several years have shown that the purity of the electrolyte is of fundamental importance. Thus, it was found that the presence in the electrolyte of the amount of organic matter derived from filter paper by the passage through it of the distilled water used, was sufficient to cause an appreciable effect upon the structure and weight of the silver deposit. In this case delicate analytical procedures were devised for detecting minute amounts of such contaminants.

CHEMICAL NEWS,

March 9, 1917

In the same research the study of the magnitude of possible occlusions in the silver deposits has involved the use of painstaking analytical methods at the Bureau and elsewhere.

Similarly, it is believed that the securing of accurate information regarding the operation of commercial baths for electro-deposition will depend largely upon the applica tion of exact analytical methods. Thus, preliminary observations have shown that very slight differences in the neutrality of nickel baths may produce great effects upon their operation. Here the application of the hydrogen electrode as an analytical tool will probably be of service. The great number of empirical observations regarding the effect of addition agents in plating baths will become intelligible only when means are found and applied for determining quantitatively minute amounts of the addition agents (for instance, one part per milion of glue) or of their decomposition products.

The application of some of the concepts of the modern theoretical chemistry has helped much to a better understanding of the limitations of some common methods, of how to reduce the errors of one or another of them withia more or less acceptable bounds, and of why others are not open to improvenient. The same principles applied to the development of new methods will, it is to be hoped, lead more quickly to success than in the past, by enabling the discoverer to take account from the start of earlier mistakes or omissions, and thus avoid the wasted effort that has been all too common.

At this point it may not be amiss to point out certain criticisms that apply to many new methods as first pub. lished. Almost no new method that has been proposed has been so vigorously worked out as to show all or nearly all of its limitations. Generally the start is with the presumably pure single substance, and the amounts operated upon are of considerable magnitude and do not cover a wide range of weights. This is not so serious a defect as to omit trying out a method that involves separations from other substances under a wide range of conditions as to relative and absolute amounts of the elements or compounds in question. A whole list is often given of results obtained in presence of other elements, but almost always the amount of the substance sought is considerable. No light is shed on the value of the method when that substance is in very small amount and the other greatly pre ponderates. Nor, in too many cases, is any proof afforded that results apparently good are really good and that more or less serious compensating errors are not involved. The consequence is often, as I have said, that one cannot take new methods at their face value or proceed to apply them under any and all conditions. They must first be more critically examined in order to complete and round out the work that was neglected. How this can be done will be discussed later.

What I have just said is not to be taken as necessarily reflecting upon the deviser of the incomplete method, nor need it deter others from trying to originate new methods or to improve old ones. There will be and must always be road breakers and pioneer surveyors. Some fertile minds are fitted to make brilliant reconnaissances and unfitted for the laborious working in of details, Both types of chemical workers are needed. The former will still find ample opportunity for flights of invention and there will be no lack of room for the able and painstaking delver into the depths.

In the address already alluded to and elsewhere I dwelt upon the unsatisfactory condition in which the art of analysis had been shown to be and expressed the conviction that our educational institutions must bear a large share of the blame in the matter. The faults which might be chargeable were perhaps more often those of omission than of commission, but I was able to point out no certain or even likely way which might lead to a better future. I think it may be worth while to reproduce certain paragraphs, with slight rearrangement, to serve not only as groundwork for what is to follow, but also as pos

sibly suggestive leaders to those of you who are or expect to become analytical chemists or teachers of analytical chemistry.

Many inquiries addressed to the participants in one series of analyses elicited the information that few knew anything definite about the quality of the water they were using, though examination showed it to be bad in a few known as to the quality of the reagents, except that they sediment showed in his ammonia bottle, but he used only came from reputable firms. One admitted that a flaky the clear liquid above. If the sediment represented silica from the bottle, as it may well have done, what had become of the other constituents of the attacked glass unless they were in solution?

instances and on the border line in others. Still less was

"Now why were these things possible unless because it had never been sufficiently impressed upon the analysts in their student days that without proper tools to work with, among which water and reagents are first to be considered, good work is impossible? You doubtless do not fail rightly to tell them that absolute accuracy is unattainable in analysis, but do you make it plain that approximation is possible and that it will be the closer the greater the care bestowed upon the tools and at every step of the analysis itself? Is a student ever required to find out by actual test how good his water is, and both the kind and amount of its contamination, if such there be? Is it customary to instruct him in the testing of his reagents and as to the character of the contaminations to be looked for in all of the more important ones, or is C. P., while not a flawless title, is a sufficient guarantee he allowed to go forth with the impression that the label for all the demands of technical analysis? Is he, in fact, which his work may be affected, due to imperfections in ever cautioned to find out, by actual test, the errors with his tools of the kind just mentioned? And that without such knowledge and the ability to make correction for the defects, or the courage to fight for better materials with which to do, he will occupy a false position with respect to himself, his employers, and the community at large?

"Is the student's work ever checked against material of which the exact composition is known? I do not refer here to such things as simple salts, but to more complex bodies like limestone, cement, zinc ore or slag, in which many separations have to be made and all constituents should be determined. Is the student in such analyses religiously required to test the purity of his precipitates and the completeness of his precipitations by a careful examination of the filtrates? And is he taught that a satisfactory summation does not imply correct separations? Or that closely agreeing duplicates are not proof of good work?

knowledge as to his own power to do good work, and "Only by such exercises can the young worker gain any acquire that proper confidence in himself which is so

essential.